A turbine engine system often includes a gas producer and a power turbine. The gas producer includes a combustion chamber for producing a high-pressure gas flow by burning a fuel supply. The high temperature, high pressure gas flow is directed into the power turbine, driving the power turbine to produce output power. Thus, monitoring and controlling the combustion chamber is important for proper operation of the turbine engine system.
Combustion instabilities in gas turbine systems can produce intolerably large pressure waves, which may lead to fatigue and failure of components and costly outages and repair. An acoustic sensor is often used to measure the dynamic pressure within the combustion chamber. The acoustic sensor provides the measurement to be used to monitor, detect, and correct instabilities before they cause serious damages. However, it is difficult to directly measure dynamic pressure within the combustion chamber due to the high temperature, high pressure environment.
U.S. Patent Application Publication No. US 2010/0139286 A1 discloses a burner including a pressure measurement device for measuring pressure in a gas turbine. The pressure measurement device includes a measuring point defining a location of the pressure measurement. The measuring point is located inside the burner of the gas turbine.
Because existing sensor components may not withstand the temperature and pressure generated within the combustion chamber, the acoustic sensor in existing turbine engine systems is often located remotely from the combustion chamber to avoid damages to the sensor. Thus, existing combustion monitoring systems require a transfer tube to transfer the pressure from the combustion chamber to the sensor. In order to prevent resonance from interfering with measurements, sensor is also connected to a semi-infinite coil, which when, filled with water due to condensation and water wash, may result in erroneous measurements. As a result, there is a need for a combustion monitoring system that uses an acoustic sensor located near the combustion chamber without an associated semi-infinite coil to directly measure the pressure therein.